docs: def to_shapefile(output, input_nrml_file, validate):
      """
      Convert a NRML source model file to ESRI Shapefile(s).
  
      For each type of source geometry defined in the NRML file (point, area,
      simple fault, complex fault, planar) a separate shapefile is created. Each
      shapefile is differentiated by a specific ending('_point', '_area',
      '_simple', '_complex', '_planar').
  
      NB: nonparametric sources are not supported.
      """
      input_parser = shapefileparser.SourceModelParser()
      source_model = input_parser.read(input_nrml_file, validate)
      if not output:
          output = os.path.splitext(input_nrml_file)[0]
      print('Extracting %s_ files' % output)
      shapefileparser.ShapefileParser().write(output, source_model)